In the production of tufted carpeting, a tufting machine, which resembles a sewing machine except that it has instead of a single needle, a whole row of needles or a couple of adjacent rows of staggered needles, is used to stitch face loops into a pre-formed layer of backing. Loopers are used in conjunction with the needles to maintain at a desired pile height the yarn loops which are being inserted. If the carpet is to be of sheared pile the looping upper ends of the pile are sheared off, often using knives which are associated scissors-fashion with the loopers.
(Tufted carpeting is to be contrasted with woven carpeting. In the production of woven carpeting, the backing is woven simultaneously with the insertion of the pile yarn.)
Generally the primary backing used for the production of tufted carpeting is a rather open-weave canvas-like textile material, e.g. made of polypropylene, especially where the carpeting is to be used out of doors, as artificial turf for a playing surface such as a football field at a stadium. Sometimes the primary backing of tufted carpet is a molded or extruded netting rather than a woven product, or it may be a sheet of extruded plastic sheeting or a non-woven sheet of interlaced and thermally bonded, non-woven plastic fibers. Generally these types of non-woven backings are for lighter-duty tufted carpeting and would be unsuitable for production of tufted carpeting-type artificial turf.
Tufted carpeting generally is made "upside down" in the sense that as the primary backing is pulled from a feed roll and across the horizontal bedplate of the tufting machine the loops are stitched downwards through the backing so that the pile is formed below the plane of the primary backing. Then, some type of adhesive and/or a secondary backing, either of which may include a layer of foamed rubber or plastic padding or self-underlayment are applied, usually in a downward direction or a sideways direction on the exposed surface which is to become the underside of the carpeting.
Artificial turf is a subcategory of tufted carpeting. It shares many qualities and manufacturing techniques in common with tufted carpeting that is used in homes, offices and commercial facilities. However, it is distinctive in needing to be especially resistant to snagging, backing-ripping and other possible personal injury-causing or personal injury-exacerbating reactions to player's rough activities carried out thereon. In general, it is an industry practice when making tufted carpeting-type artificial turf to use a heavy-duty primary backing. However, there appears to be a limit to how heavy-duty a layer of primary backing can be used. If the gauge is too fine, there is a danger of backing ripping due to unrelieved tension of the pile. If the gauge is too coarse, the pile anchoring adhesive can leak onto the face ruining the turf-like character of the product, and an unacceptable rate of damage to the tufting needles, looper mechanisms and knives may occur.